Which of the following statements is true regarding adaptive radiation?

• A. Adaptive radiation involves the rapid evolution of multiple species from a common ancestor to occupy different ecological niches.
• B. Adaptive radiation results in decreased biodiversity within an ecosystem.
• C. Adaptive radiation is the process by which unrelated species become more similar due to similar environmental pressures.
• D. Adaptive radiation only occurs in response to mass extinction events.

Answer: (A)

Verified step by step guidance

1. Understand the concept of adaptive radiation: Adaptive radiation refers to the rapid evolution of multiple species from a common ancestor, allowing them to adapt to different ecological niches. This typically occurs when new habitats or resources become available, or after events like mass extinctions that open up ecological opportunities.
2. Analyze the first statement: 'Adaptive radiation involves the rapid evolution of multiple species from a common ancestor to occupy different ecological niches.' This aligns with the definition of adaptive radiation and is likely true.
3. Evaluate the second statement: 'Adaptive radiation results in decreased biodiversity within an ecosystem.' This is incorrect because adaptive radiation typically increases biodiversity by creating new species that occupy various ecological niches.
4. Examine the third statement: 'Adaptive radiation is the process by which unrelated species become more similar due to similar environmental pressures.' This describes convergent evolution, not adaptive radiation, so it is false.
5. Assess the fourth statement: 'Adaptive radiation only occurs in response to mass extinction events.' This is incorrect because adaptive radiation can also occur in response to other factors, such as the colonization of new habitats or the availability of unexploited resources.